The objective of this project is to investigate the role of cyclic nucleotides (cAMP and cGMP) and prostaglandins (PGE 2 and PGF 2 alpha) in the mechanism of alveolar bone and periodontal ligament (PDL) remodeling during tooth eruption, root resorption and orthodontic tooth movement. The effects of hormones (parathyroid hormone and calcitonin) and drugs which affect phosphodiesterase activity (imidazole and theophylline) on cyclic nucleotide levels in tissues surrounding erupting, resorbing and moving teeth will be studied as well as the effect of these agents on prostaglandin levels. The technique used in this study will be the simultaneous extraction and measurement of cAMP, cGMP, PGE 2, PGF 2 alpha concentrations from tissues surrounding the involved teeth expressed per microgram of DNA. Identification of the bone and PDL cells which participate in the remodeling process will be done immunohistochemically by the use of monospecific antibodies against cAMP cGMP, PGE 2 and PGF 2 alpha. Moreover, alkaline phosphatose will be localized histochemically in serial sections of the same jaw to correlate enzymatic activity, related to mineralizaion, with changes in cyclic nucleotide and prostaglandin staining patterns.